Add troubleshooting section (with model architecture and custom node troubleshooting subpages)

[christian-byrne]

Resolves #101 by adding Troubleshooting section with various subpages (can be re-organized later). The major benefit of having these pages here is so that we can quickly link to them whenever someone reports an issue on the forum, discord, reddit, wechat, or GitHub Issues/discussions.

In this initial PR, I included troubleshooting subpages for 2 errors that have been repeatedly reported by users (each time requiring someone to re-explain the troubleshooting process or solution manually):

1. Custom node issues. How to efficiently diagnose and bisect custom node isssues and what to do when the culprit node is identified
2. Model architecture mismatch. Issues that arise from using incompatible architectures (see examples:Given groups=1, weight of size [320, 4, 3, 3], expected input[2, 16, 192, 128] to have 4 channels, but got 16 channels instead ComfyUI#5637, VAEDecode Given groups=1, weight of size [4, 4, 1, 1], expected input[1, 16, 144, 112] to have 4 channels, but got 16 channels instead ComfyUI#4900, Given groups=1, weight of size [64, 4, 3, 3], expected input[1, 16, 128, 128] to have 4 channels, but got 16 channels instead ComfyUI#6419, New error occuring after latest update : Given groups=1, weight of size [1536, 16, 1, 1], expected input[1, 4, 256, 256] to have 16 channels, but got 4 channels instead ComfyUI#2838, RuntimeError: Tensors must have same number of dimensions: for 2 and 3 ComfyUI#8292, The size of tensor a (49) must match the size of tensor b (16) at non-singleton dimension 1 ComfyUI#7177, and many more)

Over time, more common issues or pitfalls can be documented with solution and troubleshooting steps.

[christian-byrne]

Just got feedback on memory troubleshooting section from backend devs, will apply feedback momentarily

[comfyui-wiki]

Okay, I'm linking the troubleshooting page to another pages right now.

[comfyui-wiki]

I don't know why the Chinese Translation Sync Check always failed.

[christian-byrne]

Going to merge for now if no changes are requested. Feel free to reorganize/edit the troubleshooting pages or content later on @comfyui-wiki. Thanks!